1. Field of the Invention
An aspect of this invention relates generally to clean environments, and more particularly to portable clean environments employed in the field of molding.
2. Description of Related Art
In the molding field, it is often desirable to mold parts in a low particulate count environment. This is particularly true for medical and optical molded parts, for example. Typically, such low particulate count molding is accomplished by locating the entire mold machine within a clean environment, such as a class 100,000 clean room. However, it is generally costly to maintain such a clean room, much less a lower particulate count permanent environment on the order of class 100, and the molder is often also then limited to the particular mold machine that is installed within the clean room, creating potential problems in production scheduling and in the event of machine downtime.
To address some of these concerns common to locating a mold machine in a permanent clean room, temporary clean rooms and other portable clean environments have been developed in the art. These temporary and portable clean environments are also relatively expensive to operate and/or are generally not capable of maintaining a low particulate count environment on the order of class 100 independent of a larger clean room within which they are designed to operate.
The following art defines the present state of this field:
U.S. Pat. No. 4,723,480 to Yagi et al. is directed to a manufacturing apparatus equipped with product transfer means arranged along the flow of products and provided with an air cleaning device. A partition panel is provided on the downstream side of the clean air blow-off vent of the air cleaning device so as to form a clean air passageway and prevent dust from penetrating into the passageway, so that goods are manufactured and transferred in the cleaned air passageway.
U.S. Pat. No. 4,981,634 to Maus et al. is directed to an injection molding process that creates a micro-cleanroom environment inside a mold cavity which can stay closed to airborne contaminants while ejecting and transferring the molded part out. The molded part is formed and solidified at a parting-line plane within the mold cavity, then is carried rearward on the movable mold insert to a second plane where it is stripped off and transferred out through a discharge aperture which is open when the mold cavity is in the second plane but closed off when in the first plane. The aperture faces substantially downward to prevent entry by upwelling thermal air currents. External supplied filtered gas can provide positive pressure through vents within the moldset's internal space. This maximizes mold and part cleanliness while speeding up “mold-open” cycle and may eliminate HEPA filters/enclosures and robots. Optical disks, lenses, food packaging and medical parts are suggested uses.
U.S. Pat. No. 5,139,459 to Takahashi et al. is directed to a clean transfer method capable of safely transferring a semiconductor or the like to various apparatuses for treating the semiconductor while keeping the environment clean. In the method, the semiconductor is transferred between a vacuum clean box arranged in a clean room and kept at the degree of vacuum of 1 Torr or less and a vacuum chamber arranged in a maintenance room while transfer ports of the vacuum clean box and vacuum chamber are kept air-tightly connected to each other. The vacuum clean box is movably arranged.
U.S. Pat. No. 5,316,560 to Krone-Schmidt et al. is directed to an apparatus for controlling the environment of an enclosed space. The apparatus includes a workspace compartment within a gas-tight chamber, a mechanism for circulating dehumidified gas in true laminar flow through the workspace compartment, and a highly efficient filtering component for removing contaminants from the gas.
U.S. Pat. No. 5,401,212 to Marvell et al. is directed to an environmental control system including a modular isolation chamber. Together with associated atmospheric regulatory equipment, the connectable modular chambers provide a smaller, cost-effective alternative to the traditional clean rooms utilized for fabricating or processing semiconductors and other products. Because the work pieces and processing or other machinery are isolated from the remainder of the rooms in which they are located, decontamination of much of each room is not required. Use of the portable, modular chambers of the present invention also permits increased control over particulate contaminates smaller than heretofore satisfactorily regulated and individualized regulation of differing processing environments within a single room.
U.S. Pat. No. 5,425,793 to Mori et al. is directed to chamber units are sequentially coupled with each other to thereby provide a volume of clean space, and whereby different environments can be maintained in the different chamber units. An air blowhole or door is provided at an opening section of each chamber unit. Moreover, a space section can be defined at the coupling part of the chamber units, and a suction pump and a suction hose can be provided in the space section, so as to prevent the environments of the different chambers from influencing one another.
U.S. Pat. No. 5,464,475 to Sikes et al. is directed to an improved machine for performing a manufacturing process on a workpiece. The machine includes a cabinet defining an interior workspace for performing the manufacturing process. The workpiece is placed in the workspace by an operator. The cabinet is coupled with a gas source for receiving a flow of gas from the gas source. The improvement comprises a first aperture in the cabinet providing access to an interior chamber within the cabinet. The interior chamber has an interior surface and an open end aligned with the first aperture for storing a work-in-process unit. The interior chamber is accessible to the operator for transferring the work-in-process unit between the interior chamber and the workspace. The improvement further comprises a second aperture in the interior surface of the interior chamber, the second aperture admitting the flow of gas from the gas source to establish a laminar flow of the gas in the chamber intermediate the first aperture and the second aperture.
U.S. Pat. Nos. 5,687,542, 5,953,884 and 6,145,277 to Lawecki et al. are directed to an apparatus and method for manufacturing articles, such as syringe barrels, substantially free from contaminants. The apparatus is an enclosure defining at least a class 100 and MCB-3 environment, and includes a molding isolation module and a packaging isolation module. Any contaminants that may exist within the enclosure are removed by the use of horizontal and vertical laminar airflows directed into air filter units. Further, the molding temperature may be selected such that it renders the fabricated articles substantially free from contaminants. The molding isolation module and packaging isolation module keep the fabricated articles substantially free from contaminants from the time the articles are molded to the time the articles are placed in sealed containers for shipment.
U.S. Pat. No. 5,833,726 to Kinkead et al. is directed to a scheme for defining, inside a processing facility, a storage environment that is substantially free of a targeted molecular contaminant and in which one or more substrates are to be stored for a period of time before or after a substrate processing step; the scheme including: an air blower for providing a flow of air within a storage environment defined inside a processing facility; a substrate support for holding one or more substrates inside the storage environment; and a molecular air filter having an input face positioned to receive air from the blower and having an output face for providing a flow of filtered air inside the storage environment, the molecular air filter being constructed and arranged to remove an airborne molecular contaminant from air flowing into the storage environment to achieve a concentration level of the molecular contaminant inside the storage environment suitable for storing one or more substrates therein for a sit time corresponding to the time before a subsequent substrate processing step; wherein the storage environment is substantially free of the targeted airborne molecular contaminant. Schemes for defining substrate storage environments for semiconductor device fabrication processes are also disclosed.
U.S. Pat. No. 5,997,399 to Szatmary is directed to an apparatus for providing a clean working environment including an isolation booth, a worker booth, and an access device arranged to enable a worker in the worker booth to handle material in an isolation chamber formed in the isolation booth. A pressure generator is positioned to communicate with the isolation chamber to generate an air pressure therein that is less than the air pressure of an air curtain passing through the worker booth so that air is drawn from the air curtain in the worker booth into the isolation chamber through any air leak opening that develops in and around the access device so as to block outflow of air in the isolation chamber to the worker booth through the air leak opening.
U.S. Pat. No. 6,010,400 to Krainiak et al. is directed to an isolation work station comprising an enclosure and an air circulation system and high efficiency air filter for generating a downwardly directed laminar air flow through the enclosure. Periodic sterilization of the enclosure may be accomplished by adding a sterilant, such as vaporized hydrogen peroxide, to the airstream, and the filter is impregnated with a catalyst for degrading the vaporized hydrogen peroxide during the purge cycle and wherein the airstream is circulated at a relatively low speed so as to increase the residence time in the filter.
U.S. Pat. No. 6,238,283 to Matsuyama et al. is directed to a work conveying and transferring apparatus having a trolley having a casing defining a hermetically sealed space, and a support portion provided on the trolley for placing at least one container containing a cassette carrying works. A container opening device is provided on the trolley to open the container placed on the support portion, and a cassette transferring device is provided for transferring the cassette from the trolley to a treating apparatus, with the container placed on the support portion opened. The support portion is provided in the sealed space, and works can be double sealed by the sealed space and the container.
U.S. Pat. No. 6,623,538 to Thakur et al. is directed to a compact, portable, lightweight, low power consuming, convenient, versatile and sterile laminar airflow device, useful in obtaining a workspace substantially devoid of airborne particulate contaminants, said device having a body divided into upper and lower chambers; the upper chamber housing one or more pre-filtration members, a motor driving a fan, and one or more filters located below the motor; and the lower chamber provided with a slidable front panel, a removable platform located at the lower portion of the chamber and a perforated plane placed on the removable platform.
The prior art described above teaches a manufacturing apparatus with an air cleaning device, an injection molding process operating without opening the mold to airborne contaminants, a clean transfer method and system therefor, an environment control apparatus, an environmental control system, a coupling-type clean space apparatus, a work-in-process storage pod, an isolation module for molding and packaging articles substantially free from contaminants, storing substrates between process steps within a processing facility, an isolation chamber air curtain apparatus, an isolation workstation, a double-sealed work conveying and transferring apparatus and container inspecting method, and a sterile laminar airflow device, but does not teach a portable clean molding apparatus and method providing for the receipt of parts molded in a mold machine, manipulating such parts in a low particulate count environment, and passing the manipulated parts out of the portable clean molding apparatus without compromising its low particulate count environment, and wherein the portable clean molding apparatus and the mold machine are both not located in a clean room. Aspects of the present invention fulfill these needs and provide further related advantages as described in the following summary.